Do You Need a Fast Lens?
I’m so delighted by all the wildlife photography questions coming in right now, it’s great! A common one at the moment is, “Do I need a fast telephoto lens?” This question has been around as long as I’ve been shooting and it makes so much sense. Originally, the question came when we were shooting film and we were basically stuck at ASA64 (ASA=ISO). And while I still prefer shooting in the basement of ISO100, most raise their ISO so now the question of lens speed is not for shutter speed, but rather DoF. Just how much f/stop do you need for the DoF you desire? Your answer might cost you some bucks so here are my thoughts.
My first telephoto lens was the Nikkor 400f5.6, an incredibly sharp lens. After many years, I thought I needed speed so I went deep, first getting the 300f2.8 and then 400f2.8 lenses. Gorgeous lenses but they took a bite from the budget from this struggling photographer. That’s when I went deep into DoF and how I could make it work for me without breaking the budget. That’s when I went back to f/5.6 with the EDIF 800mm. To this day, I’m at f5.6 with either the 800AFS and 180-400VR (when the 1.4x in engaged). How then am I blowing out the DoF if shooting at f5.6? It comes back to the background as these two photos of the yearling Rocky Mtn Bighorn illustrate. When it stood up, I took its photo (the top photo). But I didn’t like that busy background of the pine tree. It’s too much in focus. I simply stepped to the right and shot again. This time, the background is not right behind the yearling but rather, way off in the distance. And since it’s off in the distance, even though both photos were taken at f/5.6, there is a difference in the DoF. Then to answer the question I pose, if you can control the background then perhaps you don’t need a fast lens. If you can save yourself a few thousand dollars by watching your background, think it’s worth the price? You might just find your own answer to the question, do you need a fast lens.
On a side note, my very talented friend Carol used the 500PF at the same time which did a killer job. Right now, Bedford Camera has a couple and if you order from them, mention the Moose Discount for special pricing, free shipping and probably no sales tax.